This invention relates generally to hacksaw frames, specifically to high tension types of frames capable of achieving the 25,000 to 40,000 P.S.I. of tension required for efficient operation of bi-metal type hacksaw blades.
Prior forms of high tension hacksaw frames such as the Bissantz et al U.S. Pat. No. 4,256,156, the Dreier U.S. Pat. No. 2,796,098, the Ewig U.S. Pat. No. 4,367,779 and the Thompson U.S. Pat. No. 4,466,471 all show some form of threaded rod tensioning device that is operated either by a lever, knurled nut, or wing nut. Additionally, many of the currently marketed frames have the majority of their tensioning mechanisms located in the handle portion of the hacksaw frame.
The threaded mechanisms previously mentioned are subject to wear and abuse that often causes the threads to malfunction or strip which prevents them from reaching their full tension, or possibly prevents them from operating at all. The wing nuts, levers and knurled nuts mentioned previously may, if located at the bottom of the handle cause an obstruction to the cutting path and prevent the most efficient use of the frame. With the tensioning mechanisms located in the handle portion of the frame, the size, and to some degree, the shape of the handle is determined by the mechanism that has to fit within it, thus producing an uncomfortable grip that promotes operator fatigue or discomfort.
It is the object of this invention to provide a hacksaw frame with an improved tensioning mechanism that overcomes the afore-mentioned problems by eliminating the threaded rods and relocating the tension mechanism away from the handle.